Study on the applicability of the wheat growth model (WCSODS ) in Henan Province

Chinese. 检验小麦模型WCSODS在河南省的适用性。采用大田方法，分别设置了播期和氮肥试验，以播期试验为基础进行参数调试，以氮肥试验验证模型。 (1）WCSODS对河南小麦生育期和产量的模拟精度较高，全生育期模拟值与实际观测值仅相差1～2 d，拔节期和抽穗期模拟相差较大，分别为3～6 d和0～4 d，产量模拟相差42～463.5 kg/ha；(2）WCSODS以绿叶分配系数和地上部干重为基础，对小麦LAI动态变化进行模拟，从而在方法上避免了叶面积定量计算时造成的误差，适用于不同分蘖能力的小麦品种，具有较好的通用性。结果显示其对LAI、茎蘖数及干物重的模拟值与实测值比较吻合，相关系数达到0.9393～0.9949；(3）WCSODS需要改进的问题是没有考虑氮肥胁迫对小麦生长发育的影响。小麦生长模型WCSODS用于河南省小麦生产的预测和决策是适宜的，但在氮肥限制下小麦的生长模拟还有待进一步完善。

English. In order to test of the applicability of the wheat growth model-WCSODS in Henan province, wheat sowing date and nitrogen fertilizer field experiments were carried out. The sowing date was experimented to adjust parameters of wheat growth and development, and nitrogen fertilizer was used to test the model. (1) There was high precision for phenophase and yield between the simulated and observed data with WCSODS. Compared with the observed, the error was 1-2 d for whole stage, 3-6 d for elongation stagel and 0-4 d for holding stage. The error of yield between simulated and observed was 2.8-30.9 kg/667m2. (2) Based on distribution index of the green leaf and dry matter above, the wheat leaf area index was simulated by WCSODS. The error caused by calculating the green leaf area was avoided in this way. The limit of the leaf area index increased with the tiller number. Wheat variety of different tiller ability was also considered in the experiment. The results showed that the observed data accorded with the simulated data of the leaf area index: the correlation coefficients between the tiller number and the dry matter weight were 0.9393-0.9949. (3) The problem remaining was that the model-WCSODS disregarded the effects of nitrogen intimidation on the growth of wheat. WCSODS is suitable model for forecasting wheat yield and wheat production in Henan province. But it will require to modification when wheat grows with limitation of nitrogenous fertilizer .